How to poison the Iran talks

An Iranian technician is seen at the International Atomic Energy Agency inspecting the site of the uranium conversion plant in Isfahan, Iran in 2007.

An Iranian technician is seen at the International Atomic Energy Agency inspecting the site of the uranium conversion plant in Isfahan, Iran in 2007. (Abedin Taherkenareh / EPA)

The Times editorial board

Over the weekend, diplomats from Iran and six major world powers finalized the details of an interim agreement designed to stop progress on the Islamic Republic's nuclear program while negotiations proceed on a permanent deal to deprive Iran of nuclear weapons. But a bipartisan group of U.S. senators continues to press recklessly for new sanctions legislation.

Sen. Robert Menendez (D-N.J.), a cosponsor of the Nuclear Weapon Free Iran Act of 2013, has called the legislation an "insurance policy" in case negotiations fail. A better description is "poison pill."

Not only would the legislation authorize new sanctions at a time when the world has decided to offer Iran relief from some previous penalties as an inducement to forswear nuclear weapons; it also ties sanctions relief to conduct by Iran that has nothing to do with nuclear power, and it expresses the "sense of Congress" that the United States should "stand with Israel" if that nation launches a military attack on Iran.

Menendez and other supporters of the legislation profess to be trying to help to President Obama as he and the leaders of the so-called P5-plus-1 — the five permanent members of the United Nations Security Council and Germany — strive to reach a comprehensive agreement with Tehran. They note that the new sanctions, including measures designed to drastically reduce Iran's oil exports, wouldn't take effect unless Iran breached commitments it already has made and refused to negotiate in good faith.

But the best judge of whether enactment of such an "insurance policy" would undermine negotiations is not Congress but the branch of government that is actually engaged in those talks. In opposing the legislation, the State Department has cited an intelligence assessment that new sanctions "would undermine the prospects for a successful comprehensive nuclear agreement with Iran." Enactment of the legislation also could fracture the international united front that has put pressure on Iran.

Obama has threatened to veto the legislation if it reaches his desk, but even if his veto were sustained — not a foregone conclusion — Congress' kibitzing needlessly complicates already delicate negotiations.

As the administration has acknowledged, an agreement in which Iran agrees to the purely peaceful use of nuclear power will be difficult to achieve. But the interim agreement, which admittedly came to pass only thanks to the pressure of U.S. and international sanctions, at least creates the possibility of such a breakthrough. If the current negotiations fail or Iran reneges on its commitments, there will be ample time for Congress to enact new sanctions. Meanwhile, the best congressional insurance policy for preventing a nuclear-armed Iran is patience.